1. Field of the Invention
The present invention relates to an image processing method. More particularly, the present invention relates to a method for tracking a moving object.
2. Description of Related Art
Visual monitoring technology becomes more important in recent years, especially after the 911 event, more and more monitoring cameras are allocated at various places. However, a conventional surveillance is generally carried out by human monitoring, or monitoring data is just stored in a storage device for later reference. As more and more cameras are allocated, the required human labour is increased accordingly, so that an automatic monitoring system applying a computer visual technique plays an important role in recent years.
The visual monitoring system analyses behaviours (such as a moving track, a pose or other features) of a moving object in a monitoring frame to detect occurrence of an abnormal event, so as to effectively notify securities for handling. A plurality of basic issues of the visual monitoring, such as background subtraction, moving object detecting and tracking, shadow removing, etc. have been studied and researched in the past. Recently, the study and research are focused on detection of high-class events, such as behaviour analysis, remnants detection, wander detection or congestion detection, etc. For a current strong demand of monitoring market, automatic and intelligent behaviour analysis may have a great demand and business opportunities.
The so-called wander detection refers that one or a plurality of moving objects is continually and repeatedly appeared in a certain monitoring region within a specific period of time. For example, prostitutes or beggars may wander about street corners, graffiti writers may stay around walls, person having intent to commit suicide may wander about a platform or drug dealers may wander about a subway station to wait their clients, etc.
However, since a camera vision of the visual monitoring system is limited, which cannot totally cover a moving path of a wanderer, when the wanderer leaves the monitoring region, the visual monitoring system then loses the monitoring object, and cannot continue the detection, especially when the wanderer returns again. Therefore, how to re-identify the wanderer to associate his former behaviour is a bottleneck for the current wander detection technique.